Lay motion for looms



Aug. 17, 1937. w. w. RoBERTsoN 090971 LAY MOTION FOR LOOMS Filed April 11. 1936 2 Sheets-SheeiI l (f --rF-hl nven or L j WiHiam W. Robertson N @fm/Nam Attor'ny Aug- 17, 1937. w. w. RGBERTSON 2,090,071

LAY MOTION FOR LOOMS Filed April l1, 1956 2 Sheetls-Sheet 2 e0 a 5w 5B Inventor WiHam W. Robertso n Attorney Patented Aug. 17, 1937 PATENT OFFIQE LAY MOTION FOR LOOMS William W. Robertson, Northboro, Mass., assignor to Crompton & Knowles Loom Works, Worcester, Mass., a corporation of Massachusetts Application April 11,

9 Claims.

This invention relates to improvements in mechanism for operating lays of relatively wide and heavy looms and it is the general object of the invention to provide an auxiliary brace to exert a force at a point intermediate the length of the lay to prevent backward bending thereof at the time of beat-up.

In relatively heavy carpet looms the reed is subjected to considerable backward force by the fabric at the time of beat-up. When the loom is relatively wide this bending leaves a noticeable curve in the pattern of the fabric being woven. Ordinarily the lay is driven by two connectors from a driving shaft, the connectors being located near the ends of the loom outside the space reserved for the harness frames. The latter are in such a position as to interfere with an intermediate connector, and it is an important object of my present invention to provide a toggle joint located in front of the harness frames and having two links one of which is operatively connected to the lay and the other of which operates from a fixed point on the loom frame, the toggle being operated by a cam set and designed to give the intermediate part of the lay a forward motion the same as that derived from the crank connectors at the ends of the lay. When the loom is running idle without warp the toggle joint will close without effort, but when the loom is weaving any tendency on the part of the intermediate portions of the lay to bend backwardly will be resisted by straightening of the toggle. By the use of my invention the dents of the reed are maintained in alignment and the successive rows of tuft yarns lie in a straight line transverse of the fabric.

It is a further object of my present invention to arrange the toggle and actuator therefor so that the toggle links do not become completely aligned, thereby permitting the toggle to bend without locking the lay as the latter recedes from forward position. This is particularly desirable when the operating force is derived from a face cam.

It is a furtherrobject of my invention to provide means to assist the lay in moving the toggle links during its forward motion. As the toggle links approach a straight or aligned relation the effort tolift them increases and this effort I somewhat relieve by a spring interposed between one of the toggle links and preferably a part moving with the lay rocker shaft. It is desirable that the spring be free from tension when the lay is forward so that as the lay starts backwardly the links will be free to drop by gravity without being resisted4 by the spring. During forward motionof 1936, Serial N0. 73,863

the lay from its rear position, however, the spring will be under maximum tension to furnish part of the force required to lift the links toward their aligned position.

With these and other objects in view which will 5 appear as the description proceeds, my invention resides in the combination and arrangement of parts hereinafter described and set forth in the claims.

In the accompanying drawings, wherein a convenient embodiment of my invention is set forth,

Fig. 1 is a vertical transverse section through a portion of a loom having my invention applied thereto,

Fig. 2 is a diagrammatic plan view of a portion of the loom having the crank connectors for the endof the lay and the toggle joint to brace the center thereof,

Fig. 3 is a view similar to a portion of Fig. 1 with the lay in rear position and the toggle broken, and

Fig. 4 is a vertical section on line 4-4 of Fig. 3.

Referring particularly to Fig. 1, the loom frame Ill supports crank and bottom shafts II and I2, respectively, which are geared together by a 2 to 1 ratio indicated at I3 in Fig. 3. The top shaft II makes one complete revolution for each forward beat of the lay L, while the bottom shaft requires two beats of the loom for a complete revolution. The loom has a breast beam I4 with a cloth board I 5 and a take-up roll I6 for the woven fabric. There are two lay swords Il and I8, one adjacent each end of the lay, and each sword is mounted on a rocker shaft I9 journaled in the bottom of the loom frame.

Connectors 20 are interposed between the cranks 2| of the shaft I I and the lay swords, and as the crank shaft I I makes one complete revolution the lay vmoves lfrom the forward position shown in Fig. 1 to the rear position shown in Fig. 3 and back again to the forward position of Fig. 1. The matter thus far described is of common construction and operates in the' usual manner.

In carrying my present invention into effect I provide an intermediate stand 30 which is rigid with the loom frame and provided with a pivot pin 3| in the upper rear portion thereof located in front of the crank shaft II. Pivoted on this pin is a rear toggle link 32 the forward end of which is pivoted .as at 33 kto a second or forward toggle link 34. The latter extends into the forked end 35 of the rear link 32.

A bracket 36 is secured to the under side of the lay beam 31 and has a pin 38 in the forward end thereof to which link 34 is pivoted. A stop screw 39 on the rear link 32 is adjusted to engage block 40 formed as part of the bracket 36, and the purpose of this stop screw is to prevent the centers 3|, 33 and 38 from becoming aligned. The center 33 is always below a line joining the pivots 3l and 33.

The bottom shaft l2 ,has secured thereto a cam v5l! having two lobes 5I and 52, respectively, which alternately engage a roll 53 on a lever 54 pivoted as at 55 to the intermediate frame 3U. The forward arm 5.3 of lever 54 is pivoted as at 5lV to an upwardly extendingrod 58 pivoted asat59 to the forked end 35 of the rear link 32. The two lobes 5l and 52 are 180 apart so that as the twopick shaft I2 rotates, lever 54. will be given a. complete oscillation for each beatof the loom.

The rear link 32 has a depending arm 65 connected as at 66 to the rearV end of a tension spring 61 the forward end of which is connected as at 68 tov an arm 39 adjustably clamped or otherwise secured to the oscillating rocker shaft I9. By this latter construction the angular relation between the arm 69 and the lay swords, and therefore the lay beam, is maintained fixed. The relation between the armsV 65'and V69 is such, however, that when the parts are positioned as set forth in Fig. 3 the rear end of thespring has moved rearwardly a greater distance than the forward end thereof, hence the spring is under maximum tension when'the lay is in the rear position set` forth in Fig. 3. When the lay is forward the effect of the differential motions of the arms 65 and 69 renders the spring slack.

lIhe lobes 5l and 52 are so designed that they preferablyl have driving relation with respect to the rolls 53 and therefore the lever 54 at such times only as the lay is near its front center position, shown in Fig. 1. Furthermore, the outer or pointed ends of these cams are so constructed as to give the toggles such a character of motion as will'move the central part of the lay beam forwardly at a rate substantially the same as that derived from the connectors of the crank shaft.

VIn operation, the top'and bottom shafts turn in the usual manner, the top shaft `effecting a movement of the lay from the rear position in Fig. 3 to the forward position of `"Fig, 1 during substantially'a half revolution of the crankshaft. During the greater part of Vthis motion the cam 5llisY out ofV driving relation with respect tothe of relation shownin Fig. 3. AAs the lay approaches forward position, however, one or another of the lobes of the cam will rock lever 54 ina left hand direction as viewed in'Figs. 1 and 3 toA elevate the rod58,V therebyrcausing the toggle links` to approachl an Aaligned position.

By the construction Yof the cam lobes already describedthe center portion of the -lay-isrmoved forwardly by the toggle at'a rate substantially the same as that of the lay'ends which derive their motions from the crank shaft, hence the lay beam will assume thefull line position shown in Fig. 3 and be prevented from bowing backwardly to the dottedY line position of that figure. As soon as the crank shaft starts to move the lay rearwardly the Ytoggle links 32 and 34 together with the rod 58,

Vthereby exerting a pull on said spring the effect of which is to rock the link 32 in a left hand direction as viewed in Fig. 3 about the axis of 3|. This has the effect of assisting the lay in straightening the toggle links, but as the lay api proaches its forward position the connection 66 moves forwardly faster than theY connection 68 and just at the extreme front center position of the lay the spring 6l is slackened so that it will not interfere in any way with the breaking of the toggle under the action of gravity when the lay starts rearwardly. The arm 69 can be clamped in adjusted angular position with respect to the rocker shaft I9 by means of the clamp screws 8U so as to vary the action of spring 61.

From the foregoing it will be seen that I have provided a simple means for bracing the intermediate part of the lay beam to maintain the latterl sists the lay in lifting the toggle joint toward the Y straightened position shown in Fig. 3, the spring however becoming slack just before the lay reaches extreme forward position so that the links 32 and 34 will be free to drop with the action of gravity when the lay starts backwardly. It will also be seen that screw 39 preventsthe toggle links Vfrom becoming completely aligned, thereby insuring easy dropping of the toggle links by gravity.

Having thus described my invention it will be seen that changes and modifications may be made therein by those skilled in the art without departing from the spirit and scope of the invention and VI do not wish to be limited to the details herein disclosed, but what I claim is:V

1. In a lay motion for a loom having a frame, a lay, a crank shaft, connectors between the shaft and lay adjacent the ends of the latter, means defining a toggle between the lay and loom frame at a point between the connectors, means lto prevent .complete straightening of the toggle, a spring Vtending to straighten the toggle Y when the lay is in Yrear positionL and means operative as the lay approaches forward position to exert a positive force on the'toggle to movethe latter toward straightened position and thereby prevent rearward bending ofthe Vlay. 2. In a lay motion for a loom having a frame, a

and lay adjacent the ends of the latter, means defining a toggle between thelay and loom'frame at a point between the connectors, means-to; prevent complete straightening ofthe toggle, a spring interposed between the lay and toggle tending to straighten the toggle when the lay is in rear position, and means operative as ,the lay approaches forward position to exerta positive force on the toggle to move the latter toward straightened. position and thereby prevent*` rearward bending of the lay.

y3. In Aalay motion for a loom having'a frame, a lay;` a crank shaft, connectors between the shaft and lay adjacent the ends of the latter, a v'toggle link connected to the 'lay ata point'between the connectors, a second toggle link pivoted to the loom frame and pivoted to the first link, yielding means between the lay and one of the links tending to move said links into alignment, stop means to prevent alignment of the links, and means operative as the lay approaches forward position to exert a positive force on the links tending to align the links to brace the intermediate part of the lay against rearward bending during the forward motion thereof.

4. In a lay motion for a loom having a frame, a lay, a crank shaft, connectors between the shaft and lay adjacent the ends of the latter, means defining a toggle between the lay and loom frame at a point between the connectors, means to prevent complete straightening of the toggle, yielding means tending to straighten the toggle, a regularly moving cam, a cam lever moved positively in one direction by the cam, and connections between the lever and toggle to exert a force on the toggle derived from the cam when the latter moves in said one direction and the lay approaches forward position to move the toggle toward straight position and thereby prevent rearward bending of the lay.

5. In a lay motion for a loom having a frame, a lay, a crank shaft, connectors between the shaft and lay adjacent the ends of the latter, a toggle link connected to the lay at a point between the connectors, a second toggle link pivoted to the loom frame and the first link, yielding means between the lay and one of the links tending to align the links, means to prevent alignment of the links, and positively acting means to move the links toward alignment as the lay approaches forward position, the lay and link connected to the yielding means operative during backward motion of the lay to increase the tendency of the yielding means to move the links toward alignment.

6. In a lay motion for a loom having a frame, a crank shaft, connectors between the crank shaft and the ends of the lay, a rocker shaft for the lay, a toggle link pivoted to the lay between the connectors, a second toggle link pivoted to the loom frame and to the rst link, an arm depending from one of the links, a second arm secured to and moving with the rocker shaft, a spring connected to the arms, means to prevent alignment of the links, a cam, and means operated by the cam and operatively connected to one of the links as the lay moves forwardly to move the links toward alignment, the arms being disposed to decrease the force exerted by the spring during the forward movement of the lay and increase said force during backward movement of the lay.

7. In a lay motion for a loom having a frame, a crank shaft, connectors between the shaft and the ends of the lay, a toggle link pivotally connected to the lay intermediate the connectors, a second toggle link pivoted to the frame and pivotally connected to the link, an arm depending from said second link, a rocker shaft for the lay,

an arm extending upwardly from the rocker shaft in front of the rst named arm, a spring connected to the arms, the arms proportioned and moving at such rates that as the lay approaches forward position the arm on the rocker shaft moves forwardly at a rate slower than that at which the said arm on the second link moves forwardly, and means to prevent alignment of the links, the force exerted by the spring decreasing as the lay approaches front center and increasing as the lay recedes from front center.

8. In a lay motion for a loom having an intermediate frame between the ends of the loom, a crank shaft, co-nnectors between the shaft and the ends of the lay, a toggle link pivotally connected to the intermediate frame at a point in front of the crank shaft, a second toggle link pivotally connected to the lay at a point intermediate the ends thereof and to the first link, means to prevent alignment of the links, and means to exert a momentary force on the links tending to move them toward alignment and cause them to move the lay at a rate substann tially the same as that caused by the connectors as the lay approaches forward position.

9. In a lay motion for a loom, a frame with i an intermediate portion between the ends of the loom, a crank shaft, connectors between the crank shaft and the ends of the lay, means located entirely in front of the crank shaft constituting a toggle between the intermediate portion of the frame and the lay at a point intermediate the connectors, and means operative as the lay ap- 

